LXR linux/arch/arm64/include/asm/jump

   1/*
   2 * Copyright (C) 2013 Huawei Ltd.
   3 * Author: Jiang Liu <liuj97@gmail.com>
   4 *
   5 * Based on arch/arm/include/asm/jump_label.h
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19#ifndef __ASM_JUMP_LABEL_H
  20#define __ASM_JUMP_LABEL_H
  21
  22#ifndef __ASSEMBLY__
  23
  24#include <linux/types.h>
  25#include <asm/insn.h>
  26
  27#define JUMP_LABEL_NOP_SIZE             AARCH64_INSN_SIZE
  28
  29static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
  30{
  31        asm goto("1: nop\n\t"
  32                 ".pushsection __jump_table,  \"aw\"\n\t"
  33                 ".align 3\n\t"
  34                 ".quad 1b, %l[l_yes], %c0\n\t"
  35                 ".popsection\n\t"
  36                 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  37
  38        return false;
  39l_yes:
  40        return true;
  41}
  42
  43static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
  44{
  45        asm goto("1: b %l[l_yes]\n\t"
  46                 ".pushsection __jump_table,  \"aw\"\n\t"
  47                 ".align 3\n\t"
  48                 ".quad 1b, %l[l_yes], %c0\n\t"
  49                 ".popsection\n\t"
  50                 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  51
  52        return false;
  53l_yes:
  54        return true;
  55}
  56
  57typedef u64 jump_label_t;
  58
  59struct jump_entry {
  60        jump_label_t code;
  61        jump_label_t target;
  62        jump_label_t key;
  63};
  64
  65#endif  /* __ASSEMBLY__ */
  66#endif  /* __ASM_JUMP_LABEL_H */
  67